1. Field of the Invention
The present invention relates in general to gaskets and particularly to FIP (Formed In Place) gaskets for an oil pan of an automotive engine or the like.
2. Description of the Prior Art
An FIP gasket is made of a room temperature setting material containing silicon and rubber as a basis. It is applied in a liquid state to the joining surfaces of two parts and then solidifies while copying the profiles of the joining surfaces. This type of gasket is progressively increasing in use in place of a preformed gasket, i.e., a gasket formed into a predetermined shape prior to installation. For example, it is used for providing a seal between the joining surfaces of an oil pan, front cover, etc. of an automotive engine.
An example of a prior art FIP gasket arrangement is shown in FIGS. 9-11. In this example, an FIP gasket 6 is used in an automotive engine to provide a seal between the joining surfaces 1a, 2a and 5 of a cylinder block 1, front cover 2 and an oil pan 4. A gasket 7 for providing a seal between the joining surfaces of the front cover 2 and the cylinder block 1 may be of the preformed type or, as shown in an enlarged scale in FIG. 10, of the FIP type. This gasket arrangement however has a problem that the gasket 6 has possibility of being separated from the joining surface 1a of the cylinder block 1 to form an opening 8 which will cause leakage of the oil pan 4, particularly when the front cover 2 is made of aluminium alloy whilst the cylinder block 1 is made of cast iron. This is due to the fact that when the engine is heated up to a high temperature, the joining surfaces 1a and 2a of the cylinder block 1 and front cover 2 are moved relative to each other to cause a gap indicated by the character "l" in FIG. 11 due to the large difference in thermal expansion between them, with the joining portion of the oil pan 4 being deformed correspondingly. Such movement may also occur, even if the cylinder block 1 and the front cover 2 are made of the same material, when they undergo heating and/or cooling by heat sources of largely different temperatures, respectively.